In recent years, as the degree of integration of, and the performance of, semiconductor devices have been increasing, fluorine-doped silicon oxide films (hereinafter referred to as “FSG films”) having low relative dielectric constants are being used for interlevel dielectric films in which multilevel interconnects are formed. Generally, an FSG film is grown in an HDP-CVD (high density plasma-chemical vapor deposition) apparatus that is suitable for filling of the fine interconnection vias.
The HDP-CVD apparatus, however, has a structure in which an electrostatic chuck is employed to hold the wafer, and is thus encumbered by a problem in that the film-growing temperature cannot be monitored. In addition, the film-growing temperature in the HDP-CVD apparatus, which is determined by factors such as RF power that is applied during film growth, cannot be measured accurately because it is difficult to measure the actual temperature using a silicon substrate that comes with a thermocouple, for example.
The present inventors therefore used the temperature measurement technique described in International Publication No. WO99/57146 to measure film-growing temperature in an HDP-CVD apparatus. In this technique, temperature measurement is carried out based on the rate at which a silicon amorphous layer on a silicon substrate is recovered.
Now, in addition to the foregoing international publication, which relates to spectroscopic ellipsometry, the following documents are relevant.
(1) Nuclear Instruments and Methods in Physics Research, B19/20, (1987), pp. 577–581.
(2) Japanese Laid-Open Pat. Publication No. H06-077301.
(3) Siemens Forsch. -u.Entwickl. -Ber.Bd. 10, (1981), Nr. 1, pp. 48–52.
(4) Japanese Laid-Open Pat. Publication No. H05-249031.